Runway sweeper



July 28, 1959 F. WlLDT RUNWAY'SWEEPER Filed Feb. 24, 1958 INV EN TOR.

W/A D 7" [fly-0U, 144 IM United States Patent G RUNWAY SWEEPER Fred Wildt, Fairbanks, Territory of Alaska Application February 24, 1958, Serial No. 717,081

8 Claims. (Cl. 15-405) This invention relates to a novel device for clearing airplane landing field runways of gravel, dirt, debris and unpacked snow. The invention is herein illustratively described by reference to the presently preferred form thereof; however, it will be recognized that certain modifications and changes therein with respect to details may be made without departing from the essential features involved.

While the presence of stones and other debris on airplane runways has always been objectionable, it becomes an acute problem in the case of jet engine airplanes because of the damage which can be done by foreign particles to internal parts of the engines, such as the compressor and turbine blades. The extreme air velocities created by jet engine operation and the great suction force at the inlet of a jet engine makes it imperative that the runway be relatively clean. This is especially important when the engines are quipped for thrust reversal employed for braking purposes during landings. In that case the forwardly directed jet stream tends to blow stones and other objects off the ground and into the suction field of the compressor. In colder climates the problem of snow accumulation is encountered making landings and sometimes take-offs dangerous or impossible.

The present invention is directed to a sweeper vehicle which is capable of covering a relatively large area in a very short period of time. Another object hereof is a practical sweeper apparatus of the type described which is practical in its construction and operation and which is versatile in its application to the various conditions encountered in sweeping airplane field runways. Furthermore, the invention is adapted for incorporation in commercially available vehicles, such as standard automotive trucks, with little or no change in the vehicle structure. In general, the invention comprises a new and improved blower type sweeper adapted for the type of use herein described and similar uses.

It is a further object, specifically, to provide such a sweeper which is so powerful in its eifect as ,to be capable of sweeping an entire runway of normal or moderate width by one passage of the sweeper down the length of the runway, and thereby enables it to be used between landings of airplanes coming in into the field at relatively close intervals and also enables it to keep a runway relatively clear of snow before the snow packs under conditions of relatively heavy snowfall. In this regard, the sweeper includes a forwardly directed blower orifice which blows the snow forwardly and off to the sides of the vehicle so that it will not be packed beneath the wheels, and which enables the lateral or branch orifices to blow such snow completely off the sides of the runway as the vehicle passes.

These and other objects, together with the novel features and advantages of the invention, comprising certain combinations of elements and in particular an arrangement of blower, blower engine, plenum duct and discharge ducts on a vehicle body, such as an automotive truck, will s ce become more fully evident from the following description by reference to the accompanying drawings.

Figure 1 is a perspective view of the novel sweeper apparatus with the blower system shown in solid lines and a conventional automotive truck upon which the same is mounted, and which completes the combination, shown by broken lines.

Figure 2 is a plan view thereof.

Figure 3 is a perspective view of the same from a rear aspect.

Figure 4 is a side view thereof at a reduced scale.

Figure 5 is a simplified perspective detailed view showing one of the engine cooling ducts and means for controlling the flow of air therethrough for regulating the cooling action.

Referring to the drawings, it will be noted that the automotive truck T shown by broken lines comprises a conventional or well-known type which includes a cab C, and a bed B mounted upon or comprising part of the truck frame. In accordance with this invention, a relatively large plenum duct 10 is mounted extending fore and aft on the truck bed. The rear portion of this duct is preferably of round cross section and extends approximately to the rear end of the truck bed. Preferably it opens to the rear to form an air inlet which is covered by a screen 12 necessary for the safety of bystanders and to prevent any objects from entering the duct and damaging the compressor blades. The compressor comprises a four-bladed airplane type propeller 14 mounted on the rearward end of a longitudinal drive shaft 16 at a location somewhat forwardly of the screen 12.

The plenum duct extending forwardly from the propeller location tapers in a longitudinal vertical plane and diverges in horizontal width. Also it curves downwardly to a level beneath the cab C, the greatest curvature occurring along the top wall thereof, 10a. The drive shaft 16, projecting forwardly from the propeller 14, passes through the downwardly sloping, upper wall 10a of the plenum duct and is connected to a radial type airplane engine 18 mounted on the bed B just behind the cab C. Thus the engine is conveniently and accessibly located outside the plenum duct, yet is directly coupled to the propeller 14, making for efficient operation of the compressor to move great quantities of air at high speed through the blower system.

As the forwardly and downwardly curving portion of the plenum duct passes below the level of the truck bed B, it branches into two lateral ducts 20 directed forwardly and outwardly from respectively opposite sides of the truck body. These branch ducts terminate in relatively long and narrow discharge orifices 22 directed somewhat forwardly and outwardly, and downwardly at a small angle. These orifices have their maximum dimension of cross section in a horizontal plane whereby they cover a relatively wide angle of sweep in removing materials from the runway as the truck advances therealong.

The plenum duct 10 extends forwardly beneath the truck frame and cab C beyond the location at which the branch ducts 20 diverge therefrom, to a central discharge orifice 30 of relatively wide dimension in a horizontal plane and a relatively narrow dimension vertically. Being forwardly directed and situated at the forward end of the truck body the orifice 30 blows snow or other loose material ahead of the vehicle and off to the sides in such a position as to be removed by the force of discharge from the branch ducts 20. This action is enhanced by flaring form a gap 34 suflicient in width and length to accommodate the drive shaft and associated components (not shown) of the truck mechanism.

Each of the branch ducts 20 has a control valve 24 therein operable by any suitable means, such as a remotely controlled relay or hydraulic actuator 26, in order to control orvary the flow of air through the individual branch ducts. Control valves 45 are also provided in the respective duct portions 32a and 32b and are controlled by individual actuators 46 in order to provide additional means for varying the relative quantities of air passing through the orifice 30 and through the branch ducts 20 and 22 in any desired manner.

In order to operate the engine 18 at the proper temperature for efficiency, bleed ducts 36 are mounted on the upper, forward wall of the plenum duct and extend forwardly therefrom to flared discharge orifices 38-. The orifices 38 are directed against the cylinder cooling surfaces of the engine 18 in order to reduce the operating temperature thereof in accordance with the amount of air bled from the plenum duct 10 in this manner. Such cooling may be regulated by means of butterfly valves 40 mounted in the respective bleed ducts 36 and positionally controlled by suitable remotely controlled actuators, such as hydraulic jacks or solenoids 42. Each such actuator is connected to a crank arm 44 operable to rotate the corresponding butterfly valve 40 to the open or closed position, in accordance with energization of the actuator by any suitable means such as thermostat means 41 mounted on or associated with the heated surfaces of the engine. In this manner the operating temperature of the engine may be maintained within the desired range.

It will of course be recognized that the specific body type of the automotive vehicle used as the base for the sweeper apparatus may vary, but it will also be evident that the apparatus lends itself to incorporation in a conventional type automotive truck and with very little if any structural modification of the truck proper. The apparatus may be manufactured of relatively inexpensive materials and at relatively low cost. By mounting the blower with its inlet directed to the rear of the vehicle and by directing the lateral orifices 22 in a forward direction as well as toward the side, there is little if any opportunity for stones and other debris to be drawn into the plenum duct. Also, the size of the plenum duct at its maximum diameter may be made as large as necessary in order to carry the necessary quantities of air and yet it will not interfere with the operators visibility nor in any way impair the maneuverability of the vehicle. Because of the powerful blower forces available and the arrangement of discharge orifices, the unit may be driven at a relatively high rate of speed over a runway and yet will sweep it effectively.

I claim as my invention:

1. Runway sweeper apparatus comprising, in combination, an automotive vehicle adapted to be driven over a runway to be swept, said vehicle having a forwardly situated drivers station and having a frame extending beneath said drivers station and projecting to the rear therefrom, a relatively large plenum duct mounted on said frame extending generally fore and aft thereon and provided with an air inlet in the rear portion thereof, said plenum duct tapering forwardly in vertical width and flaring in horizontal width and having an upper wall which slopes downwardly from a location forward of said inlet substantially to a level below that of said frame, impeller means mounted in said plenum duct at a location forwardly from said inlet for drawing air through said inlet and driving it forwardly in said plenum duct, said impeller means being mounted for driven rotation by a shaft extending generally fore and aft and through said sloping upper duct wall, an impeller drive engine connected to the forward end of said drive shaft and mounted on said frame at a relative forward location, and discharge duct means extending generally forwardly and laterally from a relative forward portion on said plenum duct to 4 conduct air therefrom, said discharge duct means terminating in at least one discharge orifice directed generally laterally and forwardly in relation to said plenum duct at a relative location on the vehicle to blow gravel and other loose materials from the runway during advance of the vehicle thereon.

2. The runway sweeper apparatus defined in claim 1, wherein the discharge duct means comprises a pair of oppositely directed discharge ducts each having a discharge orifice directed generally laterally from respectively opposite sides of the vehicle, and additional discharge duct means extending forwardly from the forward portion of the plenum duct to the forward'end of the vehicle, said additional discharge duct means comprising a relatively wide discharge orifice arranged to blow gravel and other loose material forwardly ahead of the vehicle and off to the sides in position to be blown from the runway by the lateral discharge ducts as the vehicle advances on the runway.

3. The sweeper apparatus defined in claim 2, and valve means situated in the discharge ducts and operable to vary the relative quantities of air passing through such ducts.

4. The sweeper apparatus defined in claim 2, and bleed ducts mounted on and projecting forwardly from the sloping upper wall of the plenum duct and having forward discharge ends directed against the impeller drive engine for cooling such engine by discharge of air thereon bled from said plenum duct.

5. The sweeper apparatus defined in claim 4, and thermostatically controlled valve means in said bleed ducts, operable to vary the rate of discharge of cooling air against the engine for maintaining engine temperature within a predetermined range.

6. A runway sweeper device comprising an automotive truck having a cab and a bed projecting rearwardly from said cab, a relatively large plenum duct of substantially circular cross section mounted on the top of said bed at a rearward location thereon, said plenum duct extending fore and aft on the truck and having its rearward end open to serve as an inlet for air, said plenum duct extending forwardly from said rearward end portion thereof and tapering in vertical width, said forwardly tapered portion flaring horizontally in width and curving downwardly beneath the bed, to oppositely directed lateral branch ducts having discharge ends opening forwardly and laterally from respectively opposite sides of the truck in position to blow gravel and other loose materials from the runway during advance of the truck thereon, said forwardly tapering and downwardly sloping plenum duct continuing forwardly beyond the branch ducts, and beneath the truck bed and cab to a forward terminus comprising a forwardly directed discharge orifice at the forward end of the truck adapted to blow gravel and other loose materials forwardly and to the sides of the truck as it advances on the runway, whereby such materials may eventually be blown from the runway by said lateral branch ducts, an airplane type propeller mounted in the i rearward end portion of the plenum duct, a drive shaft extending fore and aft on said truck and drivingly connected to said propeller, said shaft passing through the forwardly and downwardly sloping upper wall of the plenum duct, and a radial type engine mounted on the bed behind the cab and drivingly connected to the forward end of said shaft for turning said propeller.

7. The apparatus defined in claim 6, and bleed ducts mounted on and projecting forwardly from the upper wall of the plenum duct for directing cooling air against said engine during operation thereof.

8. The combination defined in claim 7, and valve means situated in the respective branch ducts and forward portion of the plenum duct, adapted to control relative rates of air flow through the respective ducts.

(References on following page) 5 6 References Cited in the file of this patent 2,180,269 Wisher Nov. 14, 1939 2,551,789 Copley May 8, 1951 UNITED STATES PATENTS 2,561,882 Patton July 24, 1951 1,193,475 Smith Aug. 1, 1916 2,601,695 Grace July 1, 1952 1,245,629 Smith Nov. 6, 1917 5 2,849,174 Spreng Aug. 26, 1958 

